[naga xtask] Use naga-cli's --bulk-validate option.

Use `naga --bulk-validate` for `cargo xtask validate wgsl`, reducing
runtime from 12s to 0.8s.

naga/xtask/src/main.rs

@@ -188,10 +188,16 @@ fn run(args: Args) -> anyhow::Result<()> {
  })
  }
  ValidateSubcommand::Wgsl => {
- visit_files(snapshots_base_out, "wgsl/*.wgsl", |path| {
- ack_visiting(path);
- EasyCommand::new("cargo", |cmd| cmd.args(["run", "-p", "naga-cli", "--"]).arg(path)).success()
- })
+ let mut paths = vec![];
+ let mut error_status = visit_files(snapshots_base_out, "wgsl/*.wgsl", |path| {
+ paths.push(path.to_owned());
+ Ok(())
+ });
+ EasyCommand::new("cargo", |cmd| {
+ cmd.args(["run", "-p", "naga-cli", "--", "--bulk-validate"]).args(paths)
+ }).success()
+ .log_if_err_found(&mut error_status);
+ error_status
  }
  ValidateSubcommand::Hlsl(cmd) => {
  let visit_hlsl = |consume_config_item: &mut dyn FnMut(